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Location:
Sydney
Registered:
May 2004
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Knocking noise in 7M-GE
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Thu, 14 April 2005 00:20
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Guys,
I drive an MX83 with the standard 7M-GE. I'd be greatful if anyone could shed some light on a knocking noise that has just began.
Since last night the engine has seemed rough to start and idle even after warmed up. This morning I also noticed a loud knocking noise which began after about 20 minutes into my journey and appeared to be more predominant at idle. After pulling over the noise had subsided a little thought it was still present. The noise appeared to be coming from behind the cam-belt cover. Once I'd reached my destination the noise had all but disappeared however.
Help?
Thanks!
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Location:
Adelaide
Registered:
September 2003
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 00:24
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| eluthria wrote on Thu, 14 April 2005 09:50 |
Guys,
I drive an MX83 with the standard 7M-GE. I'd be greatful if anyone could shed some light on a knocking noise that has just began.
Since last night the engine has seemed rough to start and idle even after warmed up. This morning I also noticed a loud knocking noise which began after about 20 minutes into my journey and appeared to be more predominant at idle. After pulling over the noise had subsided a little thought it was still present. The noise appeared to be coming from behind the cam-belt cover. Once I'd reached my destination the noise had all but disappeared however.
Help?
Thanks!
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Rod knock ?
What is the oil level like ? History of the motor/servicing ?
Cheers
Michael B
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Location:
Sydney
Registered:
May 2004
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 00:58
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Is that the cams moving backwards or fowards to create a knocking sound? Sorry my knowledge is rather limited  In any case though the sound seemed like it was coming from directly behind the cam-belt cover rather than further back in the head.
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What is the oil level like ? History of the motor/servicing ?
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I check the oil about two weeks ago it was a little down so I topped it up. Generally it only requires one top up between services. I service the car every 10,000 or 6 months. The engine is a low millage japanese import which was installed almost a year ago now. I'm told it came from a Japanese 97 Supra (don't go there). Mechanic who installed the engine and does work on the car though is honest and seems to know his stuff. Since installation I have had no problems at all with the motor.
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Location:
Melbourne
Registered:
May 2002
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 02:30
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get us a vid clip
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Location:
Lost in the K hole
Registered:
May 2002
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 03:21
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rod knock = crank bearing on the way out
7m's dont like low oil pressure at all, and bearings flog out easily
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Location:
Sydney
Registered:
May 2004
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 04:01
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I've just had a closer look at things and the problem seems to have gone away at the moment.
Here's some detail on what I've just done now:
A soft knocking noise began not too long after I started the engine but went away fairly quickly after reving the engine a little. The engine also seemed reasonably smooth unlike it had this morning.
I turned the engine off and I check the radiator water (from the radiator) and noticed it was very low so I put about a litre or more of water in. The over flow bottle was almost empty so I added some collant/water there too. I checked the oil and that was actually touching 'L' so I filled it up till it was touching the 'H'. I opened the heater and started the engine again and let it run for a while. The radiator cap was still off and I'd say over 50% of the water I put in was pushed out again not sure why?
I replaced the radiator cap then ran the engine for a good 15 minutes with a bit of random reving and the AC both on and off but the noise didn't return. I then took the car for a short drive and it seemed very smooth and there was no knocking sounds during or after the drive.
I hope this detail might help one of you guru's pin down what's going on with my little beasty.
No problem. Which bit would you like a clip of, the engine while it is making the knocking sound?
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rod knock = crank bearing on the way out
7m's dont like low oil pressure at all, and bearings flog out easily
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I imagine that if rod knock was related to the crank then it would be pretty loud and meaty right? Should a bearing need to be replaced, would it be a real pain in the bum job? What's likely to cause low oil presure besides a faulty oil pump?
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Location:
Melbourne
Registered:
May 2002
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 04:06
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| eluthria wrote on Thu, 14 April 2005 14:01 |
No problem. Which bit would you like a clip of, the engine while it is making the knocking sound?
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yep
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Location:
tas
Registered:
June 2002
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 10:33
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7m engine from a 97 supra, pfff i know you said not to go there, but just relize your mechanic doesn't know what he's talking about.
Boy i'd love to be able to ring him up and set him straight with his mis-information.
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Location:
Newcastle
Registered:
March 2005
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Re: Knocking noise in 7M-GE
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Thu, 14 April 2005 11:31
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| dingaling wrote on Thu, 14 April 2005 20:33 |
7m engine from a 97 supra, pfff i know you said not to go there,
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shoulda put a 1J in her
about the coolant. the reason it pushed a heap back out, is because the coolant system is all pressurised. as i'm sure you know water (and many other things) 'expands' as it gets hotter, so as your engine warms up, the coolant becomes pressurised. that's why you have a coolant overflow tank. that is also why the bottom of your radiator cap has a spring in it. as the pressure bcomes to great, it pushes up the little seal thingy, and lets the water flow out, instead of blowing your radiator to bits.
is the knock more of a 'knock' as in a rather deep almost 'thud' kind of a noise. or more like a 'tap'
does it sound likes it in the bottom end or the top
yes if it is a crank-shaft bearing.. it is most likely a 'pain in the bum' kind of job... i cant really remember what the sump on the 7m's are like, so don't know if you could get it off while under the car or have to take the engine out.. but you will most probably have to take the engine out anyhow.
if it's only a crankshaft bearing, you could probably just rip uot the crack shaft, get it ground and put oversize bearings in..
if it's more than that.......
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